You might want to post this in the Spain section, instead of the Netherlands section.

No, growing in a city hasn't made me a bad person. A few years back I found a wallet and there was no address and first I couldn't work out what to do. And then I thought: ow wait, what would my dad do: take it to the police station (so it's my dad who made me a góód person ). Anyway I went to the hoofdbureau, and the policeman was amazed "I wish everyone was as honest as you". I was going, "Huh? what else was I gonna do? just keep it?" (I'm so innocent ). So I gave all my contact details, but owner of wallet never got back to me. But hay, that's not why I handed it in, I just hope they got it back.

Only thing that I can think of in a village is that you might knów the persons whose wallet it is and then go and give it back to them personally

There is a place at the end of my road called Crunch. There are always loads of people in there on Sunday mornings, people with buggies and small kids some of them. But I've never been in there so I don't know if they have a play area.... Ow I just found their web-site: Yes they do have a play area! http://www.crunchcafe.nl/ Hope you like it!

I cannot believe the head teacher called your son an idiot! Did he say it in English or in Dutch? maybe if he was using English he actually meant in less strongly and couldnt find the right word.
Has your son said why he doesnt like it at school? Maybe changing to a school where the teacher are more understanding would help, or would that just make him more worried, having to get used to a new environment again.

You say he's smiling and playing, it doesn't sound as if he's unhappy. Is he the kind of child who would just be like that on purpose to just me miscievous (sp.?)? But then he would do that for a whole year. I think you best bet is talking to your son and his class teacher about this. Or arranging a playdate with one of the other kids / joining some kind of club where he can meet some other Dutch kids than the ones in his class, maybe he just doesnt like them or something.
I hope you manage to sort it out

There's a site called www.funda.nl which is very good for houses, but it's all in Dutch, so I don't know how far you'll get. Choose the town from this list: http://www.funda.nl/koop/browse/Sub.asp?mainClass=32
and then fill in some preferences (prijsklasse is price, aantal kamer is the number of rooms, oppervlakte woon is the living area). That should get you some of the way, and if you contact the estate agents directly they should be able help in English. Or you could post any translation queries here.

I agree with Minotaur on the school front. If it's a permanent move (i couldn't tell), I would definitely choose a local Dutch one and even if it's only temporary, it's probably still the best bet.

As for the mountain biking: you could try the dunes?

I hope I have been of some help.